446 



lOOr 



90 



MUTATION AND PLANT BREEDING 



80 



70 



60 



c 50 

 o 



a. 



40 



30 



20- 



10 



• • Diethyl Sulfate 



O O " " 



A ▲ Gamma Radiation 



A A " » 



/ 



/ 



Mutated Plants 



60 

 11/2 



80 100 Kr gamma rays 



2 Hrs., Diethyl Sulfate 



Mutagen Treatment 

 Figure 3. — Co?nparison of effects of diethyl sulfate arid gamma rays 

 on survival of M x plants and frequencies of chlorophyll-deficient muta- 

 tions in M 2 barley seedlings. 



